Silk Fibroin Nacre

Abstract Producing lightweight, mechanically strong, ductile, and biocompatible materials remains a significant challenge in material engineering due to the conflict between structural and mechanical features. Inspired by the “brick-and-mortar” structure of nacre, a construction with a naturally optimized structure-performance-function relationship, this study developed silk fibroin (SF) nacre as a silk protein-based nacre by integrating ice-templating and thermoplastic molding techniques. SF nacres are similar to natural nacre in microstructure, and their strength and toughness are even superior to natural nacres. These mechanical properties permit machining by extreme processing techniques, such as ion beam lithography. Furthermore, SF nacre can be used to modulate the polarization of laser beams and generate bright structural colors. Biocompatibility, mechanical robustness, good processability, and tunable coloration allow SF nacres to be used as a plastic replacement for structural engineering and biomedical use, showing promising advancement of such implantable devices towards clinical translation. Graphical Abstract